Hello. I want to create bow handle from carbon fiber and i have some ideas how to do that. First idea is to create 2 molds and then somehow join 2 parts i make from them. Secon idea is kame it from carbon fibre braided sleeve, but i have no experience with that. 2 mold are propably better idea but i need a way to connect those 2 modled pieces together and i need finished product to look great from outside. If anyone have better idea how to do that please share it with me.

I am using resin infusion technique, but if prepreg is only way i am happy to try it

Finished product should look like this: http://images.lancasterarchery.com/media/catalog/product/cache/1/image/13db83bec1fbd986744c31150a1b2502/2/5/2560452.jpg or search for hoyt ion x on google pictures

I'm assuming that one is made of milled aluminium?

Yes it is made from milled aluminium

You'll end up with a carbon ingot in a way. Now all you have to do is mill it

Milling carbon fiber? Is that possible? Its not a problem for me, i have access to milling machines but i never heard of milling carbon fibre. Anyway i think i will do it diferent way. I will make carbon fibre parts and then join them somehow and reinforce joints with another carbon fiber. This way i will get even lighter piece and no milling required. It will be a lot cheaper material wize and i will end up with some areas of bare carbno fibre. Joints will propably look ugly and they will have to be sanded and painted.

My idea on those joints is to bound 2 carbon fibre pieces with some epoxy based glue and then wrap around more carbon fibre tape and harden it all with resin infusion. I dont know how this will work because i want to harden only carbon fibre tape on joints not whole thing. How will it behave i have no idea. Is it problem to make resin infusion on already hardened carbon fiber? If this is problem maybe i will not use resin infusion with vacuum but only apply some resin with brush on carbon tape only.

You can mill carbon, its more like milling plastic. Although its very abrasive, so youll probably need carbide tools, but its happening more and more in the industry. Waterjet cutting is also an option for 2D cuts.

The dust isn't waste either, it can be used to make a putty for repairs.
Materials wise, youre talking about £5 a layer of 900g uni if it was 500mm x 200mm. Youll probably need about 20 - 30 layers, so between £100-£150 and about 1 hour to layup and bag. The rest is just oven and CNC time.

With your idea of laminating over a cured composite, you will get a mechanical bond but not the much stronger chemical bond that occurs when the epoxide is uncured and reacts with a co-polymer. You're also looking about a weeks worth of labour. As with most manufacturing, its not the materials that make something expensive, it's the labour.

From my point of view, I would never try to replicate the shape of an aluminium part (Cast & milled from Alu-alloy) in CF ... It would completely defeat the point of making it in CF...

I would make the bow-handle in a shape that makes use of the strenght and lightness of CF.  This would probably mean looking at how the alu-part is shaped to hold the bow limbs and the geometry of the handle part.. Then work out hot to build that up in layers of unidirectional and "standard" CF cloth.

To handle the shock from the arrow release, i would use at least one layer of kevlar cloth in the construction.

You could probably make a "plug" for the shape by building it up on the Alu part using hard foam and modeling clay.

I would build a curved hollow shape, in two parts and bond those together. I use this technique to make ultra light rifle-stocks.

Good luck!

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I Found this: http://www.hoyt.com/compound_bows/details/carbon+element+g3
Its bow with hollow carbon fibre structure and its made from tubes as i said i will do. Now i just need way to manufacture this and i am good to go

There is another technic that is coming more popular these days and the is carbon fiber forging.
I know that some carbon fiber airplane propeller hubs have replaced the aluminium hubs. They are lighter and stronger than metal.
There are places on the net that get into it so just do a search and see.
Fred

carbon forging is very strong and highly impact resistant the similarity with chopped mat ends when you take into account what actually happens to the fibre in the forging process ,it will cost you 10s of thousands in tooling however to achieve properly but car suspension wishbones are manufactured using this process